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Biomedical subjects

C Byrne

Publications and source records attributed to C Byrne.

At least 91 records · Page 5Linked to original sources
PubMed1995

Exploring the lived experiences of psychiatric nursing students through self-reflective journals.

This study explores the use of journals to identify important issues facing nursing students when learning in a psychiatric setting. During a 13-week psychiatric clinical experience, 18 third-year students kept journals describing the most significant event that occurred each week, reflecting on the impact and accompanying attitudes of that event. Throughout the clinical experience, the nursing faculty read the students' journals and provided written feedback on a bi-weekly basis. Major themes that students wrote about in their journals were identified. These included: meaningful learning, issues of the novice, relationships, control, self-reflection, and identification with clients. Keeping a journal provided the students with an opportunity to become more self-reflective in their practice. The issues identified by students in their journals may assist nurse educators to anticipate the learning needs of their students in psychiatry.

Female↗
PubMed1995

Primary structure of the V3 region of gp120 from sequential human immunodeficiency virus type 1 isolates obtained from patients from the time of seroconversion.

V3 loop sequences were compared from 5 human immunodeficiency virus type 1 (HIV-1)-infected patients over time. Three patients remained asymptomatic and 2 became symptomatic with large decrease in CD4 cell counts. The patient isolates were previously evaluated for phenotypic and antigenic properties and had different sensitivities to serum neutralization and changes in phenotype. This study showed a number of amino acid changes for the 2 symptomatic patients, each of whom progressed to AIDS during the study. The only amino acid substitution consistently associated with reduced CD4 cell counts, cytopathic effect, and progression to AIDS was Arg at position 11. Specific amino acid changes could not be correlated with increasing serum neutralization resistance or cytotropism changes. Increased loop charge was associated with a switch from macrophage to T cell tropism and a decrease in the number of CD4 cells. The study shows the importance of naturally occurring mutations in the V3 loop in controlling the biologic properties of HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Mediation by 5-hydroxytryptamine2B receptors of endothelium-dependent relaxation in rat jugular vein.

1. An 'atypical' 5-HT2 receptor which is located on the endothelium of rat jugular vein has been described. In the present study we have further defined the nature of the 5-HT2 receptor subtype present in this preparation. 2. In experiments conducted in the presence of ketanserin to preclude involvement of 5-HT2 receptors, the mixed 5-HT2B/2C antagonist, SB 200646, acted as an antagonist of 5-HT at the endothelial 5-HT receptor (pA2 = 7.2). Yohimbine, which exhibits negligible affinity for rat 5-HT2C receptors but has high 5-HT2B receptor affinity, acted as a potent but non-surmountable antagonist (pA2 > or = 7.3) in rat jugular vein. Neither yohimbine nor SB 200646 affected endothelium-dependent relaxations induced by carbachol. 3. Mianserin also acted as a surmountable antagonist (pA2 = 7.3) and the 5-HT2B agonist, BW 723C86, acted as a potent partial agonist (pEC50 [95% C L], intrinsic activity +/- s.e. mean = 7.9 [7.6-8.3], 0.84 +/- 0.04). Responses to BW 723C86 were antagonized by SB 200646 (0.3 microM) yielding an 'apparent' pA2 [95% CL] of 7.03 [6.76-7.32]. 4. These data are consistent with the presence of 5-HT2B receptors mediating endothelium-dependent relaxation of rat jugular vein.

Animals↗
PubMed1995

Hope and schizophrenia: clinicians identify hope-instilling strategies.

Nurses have many opportunities to assist individuals with schizophrenia because of the frequency and nature of their contacts. The nurses in this study believed that they can make a difference and can identify hope-instilling strategies. Strategies for rehabilitation include assisting persons with schizophrenia to set goals, seeing them as people, and joining with them on their journey of recovery. Recognizing that the establishment of the relationship is central in assisting the development of client hope, and (hopefully) eventual recovery, may help nurses to persevere despite what may be a challenging and lengthy process.

Adaptation, Psychological↗
PubMed1994

Survival advantage differences by age. Evaluation of the extended follow-up of the Breast Cancer Detection Demonstration Project.

BACKGROUND: This study considers breast cancer survival patterns by age group among women diagnosed in the Breast Cancer Detection Demonstration Project (BCDDP) to provide insight into the nature of breast cancer and suggest a possible explanation as to why the results of the randomized clinical trials differ for women younger than 50 and those 50 or older. Based on the findings of several randomized clinical trials, there is a general consensus that breast cancer screening provides a significant benefit for women aged 50-69. From these trials, there is little evidence of a short term benefit and uncertainty regarding any long term benefit of mammographic screening for women aged 40-49. METHODS: The BCDDP was not a randomized trial, but a nationwide breast cancer screening program conducted between 1973-1980, in which all participants received annual physical and mammographic examinations. Using the BCDDP data, this study calculated 14-year breast cancer survival among 4051 women diagnosed with breast cancer between 1973 and 1980 and followed through 1988 and 1989. RESULTS: In all, 598 women died of breast cancer, resulting in an overall 14-year breast cancer survival of 83.4% (standard error = 0.007). Breast cancer survival varied by tumor type, lymph node status, tumor size, and stage at diagnosis. For most of the cases, however, both the distribution and breast cancer survival rates were similar for women aged 40-49, 50-59, and 60-69 across all prognostic indicators. Only breast cancer survival among women with invasive breast cancer who had a primary tumor 5 cm or larger or with positive lymph nodes differed by age, with women aged 60-69 at diagnosis having poorer survival. Analyses by modality of detection conducted in a subset of 2739 cases indicated that the 34.6% of the cases detected by mammography alone had the highest overall breast cancer survival rates (90.9%), while the 32.2% of the cases detectable by both physical examination and mammography had the lowest breast cancer survival (79.0%). Overall, women diagnosed with breast cancer in the BCDDP had a survival advantage if diagnosed with either a smaller tumor or no positive lymph nodes, or if their breast cancer was detected by mammography alone. For women with large tumors (> or = 5 cm), the survival was 80.8% for ages 40-49, 72.1% for ages 50-59, and 61.7% for ages 60-69. DISCUSSION: Due to the higher breast cancer survival rates among women aged 40-49 with poorer prognostic characteristics, the breast cancer survival advantage for having a smaller tumor, no positive lymph nodes, or breast cancer detected by mammography alone was lower for women aged 40-49 than women aged 50 or older at diagnosis. These differences in survival advantage may help to account for the differences in mortality by age in the randomized clinical trials.

Adult↗
PubMed1994

Effect of age and diagnosis on survival of older patients beginning chronic dialysis.

OBJECTIVE: To assess the survival of elderly patients in the United States beginning chronic dialysis for end-stage renal disease caused by diabetes mellitus, hypertension, glomerulonephritis, polycystic kidney disease, and other causes. DESIGN: A secondary analysis of data obtained from the Health Care Financing Administration. PATIENTS: All Medicare end-stage renal disease patients 55 years of age or older (n = 95,394) who began chronic dialysis treatment in the US between 1982 and 1987. MAIN OUTCOME MEASURES: The 1-, 3-, and 5-year survival rates for each of six age strata and, within each strata, for each of the four most frequent causes of renal failure. RESULTS: Survival rates of dialysis patients fell precipitously, and much more rapidly for the study group than for the general population, as a function of advancing age. Older patients with diabetic nephropathy fared particularly badly, such that no patients with diabetic nephropathy aged 85 years or more survived 5 years. CONCLUSIONS: Mortality rates of patients older than 55 years beginning chronic dialysis treatment increased dramatically as age at initiation of dialysis increased. Clinically meaningful survival data should prove useful to persons making decisions about the initiation of chronic dialysis.

Age Factors↗
PubMed1994

Menopausal estrogen and estrogen-progestin replacement therapy and risk of breast cancer (United States).

This study examines the relationship between menopausal estrogen and estrogen-progestin replacement therapy and risk of breast cancer, focusing on whether associations differ according to whether the tumors are in situ or invasive. Data are from a prospective study conducted 1980-89 on 49,017 selected participants in the Breast Cancer Detection Demonstration Project, a five-year screening program conducted between 1973 and 1980 in the United States. Overall, the rate ratio for estrogen-only use compared with no-hormone use was 1.0, and that for the estrogen-progestin combination was 1.2 (95 percent confidence interval [CI] = 1.0-1.6). However, the associations differed according to whether the tumors were in situ or invasive. The rate ratios of in situ breast cancer associated with use of estrogens alone and the combination regimen were 1.4 (CI = 1.0-2.0) and 2.3 (CI = 1.3-3.9), respectively. Duration of estrogen-only use also was associated with risk of in situ tumors, with users for 10 or more years at twice the risk of nonusers (P-value for trend test = 0.02). Duration of use was not associated with risk of invasive cancer. Our results are consistent with the hypothesis that hormone replacement therapy is related to earlier-stage breast cancer; however, the possibility that the results reflect increased breast cancer surveillance among those taking hormones cannot be ruled out.

Adult↗
PubMed1994

The epidermis: rising to the surface.

At the skin surface, the epidermis serves an important protective function which it manifests by building an extensive cytoskeletal architecture of keratin filaments, spanning from the nuclear envelope to hemidesmosomes and desmosomes. Recent studies on epidermal proteins and their interactions have provided insights into human skin diseases, including genetic disorders of keratins, laminins, and collagen. Explorations into the regulatory mechanisms underlying epidermal genes have underscored the importance of transcription factors AP-1 and AP-2, retinoic acid receptors, and POU proteins. Transgenic and gene ablation experiments on TGF-alpha and TGF-beta genes have yielded clues as to how the epidermis maintains a balance of growing and differentiating cells.

Animals↗
PubMed1994

Race, socioeconomic status, and the development of end-stage renal disease.

The reasons for the increased annual incidence of end-stage renal disease (ESRD) in blacks compared with whites are unclear, but may include lack of access to treatment of the causative disease, which likely relates closely to socioeconomic status (SES). End-stage renal disease rates for diabetic glomerulosclerosis, hypertensive nephrosclerosis, and glomerulonephritis were determined in the 9,390 black and white New York State residents who began treatment within the Medicare program between 1982 and 1988. The relationship between the incidence of ESRD, age, and SES, as measured by the race-specific median family income in the patient's zip code, was estimated using a series of logistic-regression models for 12 populations: three causes of renal failure by two races by two sexes. For whites, incidence rates of diabetic glomerulosclerosis and hypertensive nephrosclerosis were significantly negatively associated with declining SES for the 45 to 65 year and 25 to 55 year age groups, respectively. In contrast, there was no relationship between the incidence of these diseases and SES in blacks. For glomerulonephritis, effects of SES were minor for both races. Better access to treatment of diabetes and hypertension might well decrease the annual incidence of ESRD due to diabetic glomerulosclerosis and hypertensive nephrosclerosis in whites. If the SES measures used for blacks are adequate, predisposition to progressive renal damage in response to renal injury or environmental factors other than SES are stronger risk factors for ESRD than SES.

Adult↗
PubMed1994

Role of cardiorespiratory abnormalities, smoking and dive characteristics in the manifestations of neurological decompression illness.

1. Blind analysis of contrast echocardiograms to detect intracardiac shunts, blind analysis of lung function tests for evidence of small airways disease, smoking history and dive characteristics were examined in an attempt to explain neurological symptoms that occurred within 5 min of surfacing from unprovocative dives. 2. Pulmonary abnormalities were significantly more frequent in those divers without intracardiac shunts (50%) than in those with shunts (0%). Smoking was more common in those divers without shunts (55% versus 15%), although this just failed to reach conventional significance levels. Divers without shunts experienced cerebral rather than spinal symptoms after significantly shallower dives with lower tissue nitrogen loads. Depths of dives, tissue nitrogen loads and clinical manifestations in those divers without shunts were similar to the findings in divers who had symptoms after rapid ascents. Despite conservative dive profiles, clinical manifestations in divers with shunts resembled those observed after missed decompression stops. 3. The findings suggest that occult lung disease, and probably smoking, increase the risk of neurological symptoms, even after unprovocative dives, and the similarity of the dive profiles and clinical manifestations to cases with rapid ascents suggest that pulmonary barotrauma and arterial gas embolism are responsible. In divers with intracardiac shunts the different dive profiles and clinical manifestations imply that there is another mechanism, involving different tissue and bubble nitrogen kinetics resulting in venous gas liberation and peripheral amplification in embolized tissues, rather than paradoxical embolism per se.

Adult↗
PubMed1994

Neutralizing antibodies against sequential autologous human immunodeficiency virus type 1 isolates after seroconversion.

The emergence of human immunodeficiency virus type 1 (HIV-1) variants with different sensitivities to serum neutralization and biologic phenotype was studied for 2-5 years after primary HIV-1 infection in 5 subjects. In 3 subjects, the initial virus isolate from seroconversion could be neutralized by autologous serum, but isolates obtained at two subsequent times exhibited reduced sensitivity to serum neutralization, decreased replication in primary macrophages, and increased ability to induce syncytia. Two of these 3 subjects progressed to AIDS and died. Sequential virus isolates from the other 2 subjects showed variability in sensitivity to serum neutralization or biologic features. These patients remained relatively stable in clinical status. Thus, viruses isolated at seroconversion appear to be either non-syncytium-inducing, strong macrophage-tropic, serum neutralization-sensitive phenotypes with stable clinical status or to have escaped neutralization by autologous sera over time, have reduced macrophage tropism and increased syncytia formation, and be associated with disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Pathways into the work force: antecedents of school and work force status.

OBJECTIVE: The study aim was to identify risk factors for specific pathways into the work force using data from the Ontario Child Health Study Follow-up. METHOD: Potential predictor variables were derived from data collected in 1983 on adolescents aged 13 to 16 years. The subjects were followed up 4 years later and the school/work force outcome was determined. Bivariate and multivariate statistical analyses were used to identify variables with a strong independent association with this outcome. RESULTS: Subjects in the work force were four times more likely than those attending school to have come from a low-income family and at least two times more likely to have a family background of low maternal education, to have failed a grade, or to have used substances heavily during early adolescence. Subjects with two or more of these risk factors were likely to be in part-time work or unemployed. CONCLUSIONS: Preventive interventions should be targeted at children from poor families, or who fail at school, or show early onset of substance abuse and other deviant behaviors. Studies are needed to further elucidate the relationship between these risk factors and pathways into the work force and beyond.

Adolescent↗
PubMed1994

Programming gene expression in developing epidermis.

As the major proteins of adult keratinocytes, keratins provide biochemical markers for exploring mouse epidermal embryogenesis. Here, we used a modified method of whole-mount in situ hybridization to track skin-specific expression of endogenous keratin mRNAs throughout embryogenesis. To monitor transcriptional regulation, we coupled this with beta-galactosidase expression of a human epidermal keratin promoter-driven transgene. These studies have radically changed our perception of how the program of gene expression becomes established during epidermal development. Specifically, we have discovered that (1) basal keratin (K5 and K14) genes are first detected at E9.5 in a highly regional fashion, and surprisingly as early as the single layered ectodermal stage; (2) the early patterns do not correlate with morphogenesis per se, but rather with regional variations in the embryonic origin of underlying mesenchyme, supporting morphogenetic criteria that early inductive cues are mesenchymal; (3) epidermal keratin genes are expressed in periderm, supporting the notion that this layer arises from ectodermal stratification, even though it is simple epithelial-like in morphology and is subsequently sloughed during development; (4) later embryonic patterns of K5 and K14 gene expression parallel proliferative capacity and not stratification; and (5) K1 and K10 mRNAs are first detected as early as E13.5, and their patterns correlate with differentiation and not stratification. These patterns of epidermal gene expression led us to explore whether potential transcriptional regulators of these genes are expressed similarly. We show that AP2 (but not Sp1) cRNAs hybridize in a pattern similar to, but preceding that of basal keratin cRNAs. Finally, using gene expression in cultured cells, we demonstrate that AP2 has a strong inductive effect on basal keratin expression in a cellular environment that does not normally possess AP2 activity.

Adaptor Protein Complex 2↗
PubMed1994

The defining characteristics of support. Results of a research project.

Support is a central concept in nursing practice; not only for psychiatric nurses, but for all nurses. Yet, the ambiguity about the definition of support is troubling. More importantly, nurses are "doing things" to and for patients, but are these interventions truly supportive? What kinds of support do our patients want and need? As nursing advances towards a scientific basis for practice, we must be clear about the what and why of our actions (Sebastian, 1990). As nurses become more outcome oriented, we must know what patients value in their treatment. This study is an initial attempt to clarify for psychiatric nurses the concept of support; may it be the first of many.

Adult↗